After having his request to be upgraded to business class denied, he angrily remarked, "I hate Americans," but boarded the flight in coach class, police say.

Shortly thereafter, Jernnard was allegedly discovered by a flight attendant and the co-pilot in the cockpit sitting in the jump seat located directly behind the pilot's seat. He apparently was able to gain access to the cockpit by dressing as an Air France pilot.

"He was wearing a white button-down shirt, which had and Air France logo about the chest area," Walker said.

But flight staff was suspicious, and when Jernnard was unable to present acceptable identification, the flight attendant and co-pilot asked him to return to the cabin. The police were called and arrested Jernnard upon arrival, finding fake crew credentials and some Air France decals in his bags.

"The flight was never in danger of taking off," Walker said. "The FBI is looking into the case with the U.S. Attorney. We are trying to make a determination as to the motivation of the gentleman," he said.

For its part, Air France said the impersonator's ID badge was a shoddy forgery.

"This person was not wearing an Air France uniform or badge (Crew Member Certificate)," according to a statement from Air France." "Regarding the badge, it was a very bad fake badge, which in no way resembled the Air France Crew Member Certificate (CMC)."

Jernnard is charged with forgery, criminal trespassing, making false identification to law enforcement, false impression. He has been arraigned and was being held on $1 million bail.

Jernnard had to surrender his passport as a condition of his bail, said Tasha Jamerson, a spokeswoman for the Philadelphia District Attorney's Office.

He will not enter a plea until four weeks after his arrest, said Jamerson, in accordance with protocols of the Philadelphia court system.

Shawn Hawes, a spokeswoman for the Philadelphia Prison System, said Jernnard is in custody at Curran-Fromhold Correctional Facility.

He has no attorney yet, she said.

Jernnard's next scheduled court appearance is April 5 in Philadelphia. If the FBI and U.S. Attorney's Office decide to bring federal charges against him, he could appear in federal court today.